Device for adjusting the bottom margin on typewriting and similar office machines



Oct. 3, 1950 s. PILZER 2,524,571

DEVICE F OR ADJUSTING THE BOTTOM MARGIN 0N TYPEWRITING AND SIMILAR OFFICE MACHINES Filed Dec. 26, 1947 'INVENTOR Patented Oct. 3, 1950 DEVICE FOR ADJUSTING THE BOTTOM MARGIN N TYPEWRITING AND SIMILAR OFFICE MACHINES Severin Pilzer, Zurich, Switzerland Application December 26, 1947, Serial N 0. 794,330 In Switzerland January 8, 1947 11 Claims. 1

My present invention relates to devices for limiting the lower margin on paper sheets used in typewriters and similar line-by-line recording machines.

It is an object of my present invention to provide a device of the above type which is simple in construction and eas to operate.

With the above object in view, I propose to include in a device of the above type blocking means for automatically preventing turning of the typewriter platen when the predetermined bottom margin of the paper sheet is reached.

I have found it advisable to combine with a device of this. type also means for automatically locking the keyboard of the typewriter when the predetermined bottom margin of thepaper sheet is reached.

A preferred embodment of my present invention omprises in combination a cylindrical member secured to the typewriter platen coaxially with the same at one end thereof, a spiral groove in the surface of the cylindrical member, a flange turnably mounted on the outer end, of the cylindrical member, securing means for preventing turning ofthe flange relative to the cylindrical member when inproper position, a stop pinmounted on the flange, follower member mounted on the typewriter carriage for movement in the direction of the longitudinal axis of the typewriter platen and adapted to abut against the stop pin, said follower member engaging the. spiral groove so as to 'be moved in longitudinal direction of the typewriter platen during turning of the same, locking means operated by the follower member for automaticall preventing turning of the typewriter platen in the advancing direction when the predetermined bottom margin of the paper sheet is reached, and locking means also operated by the follower member for automatically locking the key board of the typewriter when the predetermined bottom margin of the paper sheet is reached.

A particularly preferred device according to my present invention is composed of a shaft secured to the typewriter platen coaxiall with the same at one end thereof, a cylindrical member tant from the axis of the same, a stop pin adapted to be introduced into any one of the holes and to be removably positioned within the same, a.

follower member mounted on the typewriter car-. riage for movement in axial direction of the typewriter platen, a projection having the shape of a portion of a'screw thread fitting into the spiral groove, this projection being mounted on the follower member and firmly secured thereto and adapted to abut against the stop pin and engaging the spiral groove so as to be moved in longitudinal direction of the typewriter platen during turning of the same, locking means operated by the follower member for automaticall preventing turning of the typewriter platen in the advancing direction when the predetermined bottom margin of the paper sheet is reached, locking means also operated by the follower member for automatically locking the key board of the typewriter when the predetermined bottom margin of the paper sheet is reached, said locking means including a lever arm movably secured to the typewriter carriage and located in the path of said follower member when the same reaches its locking end position, a cam mounted on said cylindrical member and located in the path of the lever arm when the same has been moved by the follower member, and a locking bar extending over the entire length of the typewriter carriage and releasable by the lever arm so as to lock the key board when the lever arm is moved by said cam.

The novel features which I consider as characteristic for my invention are set forth in particular in the appended claims. The invention itself, however both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

Fig. 1 shows a plan view, with omission of all parts not required for proper understanding of my invention;

Fig. 2 shows a detail of my new device, in cross section Fig. 3 shows an elevation of the device shown in Fig. 1;

Fig. 4 shows a sectional view of my new device, taken along line IV--IV of Figure 1;

Figs. 5 and 6 show modifications of the device shown in Figs. 1 to 4; and

Fig. '7 shows a detail of the device shown in Figs. 1 to 4.

. In my new dev e. a cylinder 4 is mounted on the shaft I of the platen 3 which, in turn, is mounted by known means in the typewriter carriage 2.

This cylinder 4 is located between a collar 5 and a knob 6, by means of which the platen 3 may be manually rotated.

By means of a screw I having a head 8 and a, gripping portion 9, the cylinder 4 may be securely clamped between the collar 5 and the knob 6, thus connecting it rigidly with the shaft I. This connection may alternatively be effected'by means of a nut acting between the cylinder 4 and the platen knob.

A pin I mounted on the knob 6 engages a slot II inthe shaft I.

The cylinder 4 is provided with a spiral groove I2 which receives the projection I3 on the follower I4. This follower I4 is slidably-mounted on a rod I5 attached to the typewriter carriage 2.

The follower I4 may either have been cut from a screw fitting into the cylinder groove I2, so that the remainding thread portion engages the groove I2, or else possess one or more pins projecting into the groove I2.

The cylinder 4 bears a cam I8 and a flange I6 with projection II, which last operates in conjunction with the follower I4. The said projection Il may be mounted either fixedly or adjustably, either on the flange or on the cylinder itself, or alternatively in the groove.

The flange I6 may, e. g., bear a series of plain or tapped holes disposed along a circular are at such intervals that when a corresponding pin on the projecting element is inserted or screwed into one of the said holes, theindicating edge thereof will coincide with the divisions on the scales.

The projection I"! may alternatively be fastened to a disc 39 as shown in Fig. 5 ,or rotatably mounted between the cylinder l and a nut 40, the latter being tightened to set the disc.

The disc 39 may bear holes as above described; in this case, a pin is provided in the lateral face of the cylinder 4 to engage one of the holes when the disc 39 is pushed upon it.

The follower I4 possesses a finger which acts in conjunction with one arm 2| of the two armed lever 22 rotatably mounted on the carriage 2. action of a spring 28 and bears a hook 24 intended to engage a catch 25 on the guide member 26. This guide member 26 and anothersimilar guide member are freely turnably attached to the two lateral faces of the carriage 2. These two guides jointly support the rod 21 which extends along the back of the carriage 2 throughout its entire length.

At the rear of the typewriter frame G, in the approximate center of its length, there is arranged a vertically controllable control element 39, whose upper bent portion 3I is governed by the rod 21, and whose lower bent extremity rests upon a single-armed lever 33 pulled upwards by a tension spring 34. I

The lever 33 bears a projection 35 which may be brought into the path of a feeler 36,- the latter being displaced towards the rear whenevera key is struck. v

The mode of operation of my new device is as follows: The cylinder 4 is released by slightly relieving the screw I by means of the grip 9. The platen 3 may now be rotated at will.

Then the sheet of paper B is inserted between the platen and the paper guide and is fed until The other arm 23 is subjected to the its upper edge K is in line with the upper terminal edge 3'! of the guide plate or so-called line scale (Fig. '7), which also serves to rectify the sheet. 7

Instead of the line scale, some other part of the typewriter, whether existing or introduced for the purpose, may be used to locate the upper edge of thepaper, or alternatively some printed or other mark thereon. The cylinder 4 is then turned back until the projection II comes into contact with the follower I5 which should be at least nearly adjacent to the flange I 6.

In the absence of a projection, the follower I4 may alternatively be brought to some arbitrarily selected'scale division or otherwise determined point, thence to begin its motion after tightening of the screw I.

When screw 1 is tightened, the cylinder 4 is I connected rigidly to the shaft I.

In writing, the platen 3 will of course be rotated discontinuously, i. e. line by line, or with the soft roller. This rotation is transmitted to the cylin-- der 4, resulting in a progressive displacement of the follower I4 in the direction of the arrow shown in Fig. 1. In the course of this movement, the cam I8 on the cylinder 4 passes between the lateral face of the carriage 2 and the lever arm 2 I without touching the latter.

Towards the end of its movement, the finger 20 of the follower I4 strikes the arm 2I and moves it towards the left against the action of the spring 22a so that it enters the path of the cam I8 and is depressed by the latter.

This disengages the hook 24 from the catch 25 of the guide 26. The rod 21 then drops upon the portion 3| of the control member 30, which is thereby depressed and operates the lever 33.

The projection 35 on the latter enters the path of the feeler 36 in such a manner that the latter can move only slightly when one of the keys is struck. As a result, the key is deprived of its usual free motion-and the type is prevented from reaching the paper.

Since after the lever arm 2I is depressed the cam I8 strikes the rear end of the follower I4, further advance of the platen is likewise prevented.

In simplified form, the part SI of the control member may, as shown in Fig. 6, be pushed up by a spring 38 or drawn up by a tension spring and thus held in the position where writing is possible, while the same is depressed by the rod 21 dropping upon it so that its termination 32a enters the path of the feeler 36 and locks the keys.

The length of the spiral groove I2 is chosen so that the follower I4 approaches the end of the groove when the sheet of paper is full. The portion 4a of the cylinder is likewise spiral in form and bears at least one scale 41) with numerals running e. g. from 1 to 72 (for the singlespace setting) and corresponding to the maximum number of lines to be written on one sheet.

Consequently, if after inserting and clamping the paper, and before beginning to write, the cylinder 4 is so adjusted that e. g. the numeral 66 (instead of 72) exactly coincides with the indicating edge I la of the follower I4, then after 66 lines have been written the cam I8 will depress the arm 2I and thus lock the key board as described above.

The result is therefore that a space equivalent to six lines will remain blank at the bottom of the sheet. Any desired bottom margin can be obtained in this manner.

Since the scale divisions correspond to .the line intervals, and approach or withdraw from the follower proportionally or otherwise corresponds ingly to the rotation of the platen, and since these scale divisions are numbered progressively or retrogressively, th indicating edge of the follower shows the number of lines maining to be written at each point. 1

'To remove the sheet from the machine, the screw 1 is loosened.

If it is desired to continue to Write into the written or reestablished margin, the cylinder is turned back 7' slightly and-the rod 2! is. returned into position. If it is desired to use the typewriter with my device out of operation, screw 1 has to be loosened and rod 21 must be in its upper position.

The following manual operations are to be performed before typing a sheet: Loosen screw 1-; Q insert sheet; align upper edge of paper with line scale; revolve follower by turning cylinder by means of flange l6 until the projection I1 is reached, or up to desired scale division or other mark; tighten screw 1; and position rod 21.

Since any typewriter permits writing with various line intervals, the cylinder 4, or part 4b thereof, is provided with'several adjacent scales corresponding to the various line intervals. To save space in portable machines, the turns of the scales may be marked on another parallel to it, rotatable in such a manner that the scale cor responding to the selected line interval may be turned towards the indicator. r

The scales 42) may me marked with letters of the alphabet, or alternatively with symbols in color, instead of with numerals. The present device may conveniently take the form of an auxiliary attachment to present standard typewriters, portables, or other office recording machines, without substantial modification. It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of margin limiting devices, differing from the types describedabove. v 1

While I have illustrated and described'the invention as embodied in'margin limiting devices for typewriters, I do not intend to be limited to spiral groove may be very close together, with the scales placed beyond the last turn. The number of lines remaining to be written will then be indicated during the last revolution only.

' However, since the indicating edge of the follower M must be at least as wide as all the scales together, it will enter the scale segment before the last revolution is reached. A. limiting line or band will therefore be marked, possibly in color, along or between the numerals, with a similar line or band on the follower in that position where it is entering upon the last turn, in such a manner that the two marks will then be colinear and appear to coincide, but will appear as a broken line in every other position of the follower.

of the carriage 2, the rod is enabled to act on the control member 30 in any position of the carriage.

- The rod 21' can alternatively be retained in its upper position by means of a spring or be depressed by the action of the cam [8. .Likewise, the rod 2"! may rest upon the arm 3| of the locking member 30, provided the arm is retained in upward position by a tension or compression Spring. This spring will have to be designed so that the locking member remains stationary in spite of the load imposed by the rod. If, however, the rod is depressed by aid of the cam la, the locking element 30 moves downwards, thus locking the'key board. If the cylinder is backed up, the locking member 30 rises together with the rod resting upon it and releases the key board.

Obviously, many alternative designs of the controlling and locking means are possible. Thus, a rail bearing the spiral groove may be mounted in a suitable position in front of the platen, in which case the rail may be regarded as an ace tual rectification of the cylinder portion 4a hear ing the scales 4b. In this event, an indicator corresponding to the follower l4 rides on this rail and similarly'afiords a setting means for the desired margin, aswell as actuating the locking of the keyboard. l

Instead of appearing on this same rail, the

the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of my invention. 1 Without further analysis, the foregoing will so fully reveal the gist of my invention that others can by applying current knowledge readily adapt it forvarious applications'without omitting features that, from the standpoint of prior art, fair 1y constitute essential characteristics of the gen eric or specific aspecs of this invention, and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What I claim as new and desire to secureby Letters Patent is:

1. Device for limiting the bottom margin of Y paper sheets in typewriters and similar line-byline recording oilice machines comprising in combination actuating means operated by turning of the typewriter platen and including a cylindrical member secured to the typewriter platen coaxially with the same at one end thereof, a spiral groove in the cylindrical surface of said'cylindrical member, a stop member at the outer end of said cylindrical member, and a follower member movably mounted on the typewriter carriage and adapted to abut against said stop member, said follower member engaging said spiral groove so asto be moved in longitudinal direction of Said typewriter platen' during turning of the same; locking means cooperating with said follower member for automatically preventing turnin of the typewriter platen in the advancing direction when the predetermined bottom margin of said paper sheet is reached; and locking means controlled bysaid follower member for automatically locking the key board of the typewriter when the predetermined bottom margin of the 4 paper sheet is reached.

2. Device for limiting the bottom margin of paper sheets in typewriters and similar line-byline recording office machines comprising in combination actuating means operated by turning of the. typewriter platen and including a cylindrical member secured tov the typewriter platen, coaxially with the same at one end thereof, a, spiral groove in the surface of said cylindrical member, a flange mounted on the outer end of said cylindrical member, a stop pin mounted on said flange, and a follower member mounted on said typewriter'carriage for movement in the direction of the longitudinal axis of said typewriter platen and adapted to abut against said stop pin, said follower member. engaging said spiral groove so as to be movedv in longitudinal direce 7 tion of said t pewriter platen during turning of the same; locking means cooperating with'said follower member for automatically preventing turning of the typewriter platen in the advancing direction when the predetermined bottom margin of said paper sheet is reached; and lock ing means controlled by said follower member for automatically locking the key board of the typewriter when the predetermined bottom margin of the paper sheet is reached.

3. Device for limiting the bottom margin-of paper sheets in typewriters and similar line-byline recording oflice machines comprising in combination a cylindrical member; securedto the typewriter platen coaxially with theysame at one end thereof; a spiral groove in the, surface of said cylindrical member; a flange turnably mounted on the outer end of said cylindrical member; securing means for preventing turning of said flange relative to the cylindrical member when in proper position; a stop pin mounted on said flange; a follower member mounted .on said typewriter carriage for movement in the direction of the longitudinal axis of said typewriter platen and adapted to abut against said stop pin, said follower member engaging said spiral groove so as to be moved in longitudinal direction of said typewriter platen during turning of the same; locking means cooperating with said follower member for automatically preventing turning of the typewriter platen in the advancing direction when the predetermined bottom margin of said paper sheet is reached; and locking means controlled by said follower member for automatically locking the key board of the typewriter when the predetermined bottom margin of the paper sheet is reached.

4. Device for limiting the bottom margin of paper sheets in typewriters and similar line-by line recording office machines comprising in com bination a cylindrical'memberfsecured to the typewriter platen coaxially with the same at one end thereof; a spiral groove in the surface of said cylindrical member; a flange turnably mounted on the outer end of'saidfcylindrical member; securing means for preventing turning of said flange relative to the cylindrical member when in proper position; a series of holes arranged in said flange equidistant from, the axis of the same; a stop pin adapted to be introduced into any one of said holes and to be removably positioned within the same; a followermember mounted on said typewriter carriage for movement in the direction of the longitudinal axis of said typewriter platen and adapted to abut against said stop pin, said follower member ene gaging said spiral groove so as to be moved; in longitudinal direction of said typewriterplaten during turning of the same;.lockingmeans cooperating with said follower member for; automatically preventing turning of the typewriter platen in the advancing direction whenthepredetermined bottom-margin of saidpaper vsheet is reached; and locking means controlled by, said follower member for automatically lockingthe key board of the typewriter when the predetermined bottom margin of the paper, sheet .is reached. I

5. Device for limiting the bottom margin of paper sheets in typewriters and similarline-byline recording office machines comprising in com bination a cylindrical member secured to the typewriter platen coaxially with the same at one end thereof; a spiral groove in the surface of said cylindrical member; a flange turnably mounted on the outer end of said cylindrical member; securing means for preventing tuming of said flange relative to the cylindrical member when in proper position; a series of holes arranged in said flange equidistant from the axis of the same; a stop pin adapted to be introduced into: any one of said holes and to be removably positioned within the same; a follower member mounted on the typewriter carriage for movement in axial direction of said typewriter platen; a projection on said follower member firmly sec'ure'd thereto and adapted to abut against said stop pin and engaging said spiral groove so as to be moved in longitudinal direction of said typewriter platen'during turning of the same; locking means cooperating with said follower member for automatically preventing turning of the typewriter platen in the advancing direction when the predetermined bottom margin of said paper sheet is reached; and locking means controlled by said follower member for automatically locking the key board of the typewriter when the predetermined bottom margin of the paper sheet is reached.

6.- Device for limiting the bottom margin of paper sheets in typewriters and similar line-byline recording office machines comprising in combination a cylindrical member secured to the typewriter platen coaxially with the same at one end thereof; a spiral groove in the surface of said cylindrical member; a flange turnably mounted on the outer end of said cylindrical member; securing means for preventing turning of said flange relative to the cylindrical member when in proper position; a series of holes arranged in said flange equidistant from the axis of the same; a stop pin adapted to be introduced into any one of said holes and to be removably positioned within the same; a follower member mounted on the typewriter carriage for movement in axial direction of said typewriter platen; a projection having the shape of a portion of a screw thread fitting into said spiral groove, said projection being mounted on said follower member and firmly secured thereto and adapted to abut against said stop pin and engaging said spiral groove so as to be moved in longitudinal direction of said typewriter platen during turning of the same;'locking means cooperating with said follower member for automatically preventing turning of the typewriter platen in the advancing direction when the predetermined bottom margin of said paper sheet is reached; and locking means controlled by said follower member for automatically locking the key board of the typewriter when the predetermined bottom margin of the paper sheet is reached.

'7. Device for limiting the bottom margin of paper sheets in typewriters and similar line-byline recording office machines comprising in combination a shaft secured to the typewriter platen coaxiallywith the same at one end thereof; a cylindrical member turnably carried by said shaft; means for locking said cylindrical member non-turnably to said typewriter platen and said shaft whenever desired; a spiral groove in the surface of said cylindrical member; a flange turnably mounted on the outer end of said cylindrical member; securing means for preventing turning of said flange relative to the cylindrical'member when in proper position; a stop pin mounted on said flange; a follower member mounted on said typewriter carriage for movement in the direction of the longitudinal axis of said typewriter platen and adapted to abut against said stop pin', said-follower member engaging said spiral groove so as to be moved in longitudinal direction of said typewriter platen during turning of the same; locking means coopcrating with said follower member for automatically preventing turning of the typewriter platen in the advancing direction when the predetermined bottom margin of said paper sheet is reached; and locking means controlled by said follower member for automatically locking the key board of the typewriter when the predetermined bott'om 'margin of the paper sheet is reached.

8. Device for limiting the bottom margin of paper sheets in typewriters and similar line-byline recording ofllce machines comprising in combination a shaft secured to the typewriter platen coaxially with the same at one end thereof; a cylindrical member turnably carried by said shaft; means for locking said cylindrical member non-turnably to said typewriter platenand said shaft whenever desired; a spiral groove in the surface of said cylindrical member; a flange turnably mounted on the outer end of said cylindrical member; securing means for preventing turning of said flange relative to the cylindrical member when in proper position; a series of holes arranged in said flange equidistant from the aXiS of the same; a stop pin adapted to be introduced into any one of said holes and to be removably positioned within the same; a follower member mounted on the typewriter carriage for movement in axial direction of said typewriter platen; a projection having the shape of a portion of a screw thread fitting into said spiral groove, said projection being mounted on said follower member and firmly secured thereto and adapted to abut against said stop pin and engaging said spiral groove so as to be moved in longitudinal direction of said typewriter platen during turning of the same; locking means cooperating with said follower member for automatically preventing turning of the typewriter platen in the advancing direction when the predetermined bottom margin of said paper sheet is reached; and locking means controlled by said follower member for automatically locking the key board of the typewriter when the predetermined bottom margin of the paper sheet is reached.

9. Device for limiting the bottom margin of paper sheets in typewriters and similar line-byline recording oflice machines comprising in combination a cylindrical member secured to the typewriter platen coaxially with the same at one end thereof; a spiral groove in the surface of said cylindrical member; a flange turnably mounted on the outer end of said cylindrical member; securing means for preventing turning of said flange relative to the cylindrical member when in proper position; a stop pin mounted on said flange; a follower member mounted on said typewriter carriage for movement in the direction of the longitudinal axis of said typewriter platen and adapted to abut against said stop pin, said follower member engaging said spiral groove so as to be moved in longitudinal direction of said typewriter platen during turning of the same; and locking means controlled by said follower member for automatically locking the key board of the typewriter when the predetermined bottom margin of the paper sheet is reached, said locking means including a lever arm movably secured to said typewriter carriage and located in the path of said follow r mem er w n t e 10 same reaches its locking end position, a cam mountedon said cylindrical member and located in the path of saidlever arm when the same has been moved by said follower member, and a looking mechanism operated by said lever arm when the same is moved by said cam.

10. Device for limiting the bottom margin of paper sheets in typewriters and similar line-byline recording oilice machines comprising in combination a shaft secured to the typewriter platen coaxially with-the same at oneend thereof-fa cylindrical member turnably carried by said shaft; means for locking said cylindrical member non-turnably to said typewriter platen and said shaft whenever desired; a spiral groove in the surface of said cylindrical member; a flange turnably mounted on the outer end of said cylin drical member; securing means for preventing turning of said flange relative to the cylindrical member when in proper position; a series of holes arranged in said flange equidistant from the axis of the same; a stop pin adapted to be introduced into any one of said holes and to be removably positioned within the same; a follower member mounted on the typewriter carriage for movement in axial direction of said typewriter platen; a projection having the shape of a portion of a screw thread fitting into said spiral groove, said projection being mounted on said follower member and firmly secured thereto and adapted to abut against said stop pin and engaging said spiral groove so as to be moved in longitudinal direction of said typewriter platen during turning of the same; locking means cooperating with said follower member for automatically preventing turning of the typewriter platen in the advancing direction when the predetermined bottom margin of said paper sheet is reached; and locking means controlled by said follower memher for automatically locking the key board of the typewriter when the predetermined bottom margin Of the paper sheet is reached, said lastmentioned locking means including a lever arm movably secured to said typewriter carriage and located in the path of said follower member when the same reaches its locking end position, a cam mounted on said cylindrical member and located in the path of said lever arm when the same has been moved by said follower member, and a locking mechanism operated by said lever arm when the same is moved by said cam.

11. Device for limiting the bottom margin of paper sheets in typewriters and similar line-byline recording office machines comprising in combination a shaft secured to the typewriter platen coaxially with the same at one end thereof; a cylindrical member turnably carried by said shaft; means for locking said cylindrical member non-turnably to said typewriter platen and said shaft whenever desired; a spiral groove in the surface of said cylindrical member; a flange turnably mounted on the outer end of said cylindrical member; securing means for preventing turning of said flange relative to the cylindrical member when in proper position; a series of holes arranged in said flange equidistant from the axis of the same; a stop pin adapted to be introduced into any one of said holes and to be removably positioned within the same; a follower member mounted on the typewriter carriage for movement in axial direction of said typewriter platen; a projection having the shape Of a portion of a screw thread fitting into said spiral groove, said projection being mounted on said follower member and firmly secured thereto and adapted to abut against said stop pin and engaging said spiral groove so as to be moved in longitudinal direction of said typewriter platen during turning of the same; locking means cooperating with said follower member for automatically preventing turning of the typewriter platen in the advancing direction when the predetermined bottom margin of said paper sheet is reached; locking means controlled by said follower member for automatically locking the key board of the typewriter when the predetermined bottom margin of the paper sheet is reached, said lastmentioned locking means including a lever arm movably secured to said typewriter carriage and located in the path of said follower member when the same reaches its locking end position, a cam mounted on said cylindrical member and located in the path of said lever arm when the same has been moved by said follower member; and a locking bar extending over the entire length of said typewriter carriage and engaging said lever arm so as to lock said key board when said lever arm is moved by said cam.

SEVERIN PILZER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 706,136 Weir Aug. 5, 1902 770,933 Shepard Sept. 27, 1904 983,340 Zumpe Feb. 7, 1911 1,726,487 Hoellrigl Aug. 27, 1929 2,325,234 Albuquerque July 27, 1943 

